The recycling of wrecked cars now represents a substantial business. Such vehicles are first stripped of non-metal parts and hazardous materials, then crushed or flattened to consume less space during transport to a recycling station where they are chipped into small pieces. The small pieces are then sold to be melted down.
Standard flatbed trailers are commonly used to transport the crushed or flattened vehicles. The flattened vehicles are typically loaded on the flatbed in stacks using a fork-lift, and each stack is secured with tie-down chains.
There are disadvantages associated with the use of flatbed trailers, however. For one, when the wrecked vehicles are crushed or flattened, stress is put on various parts such as mirrors and moldings that may become dislodged or loose in transit, resulting in dangerous debris on the highway. Another disadvantage is that if the load has shifted, adjustments should be made to the tie-downs, which are difficult to inspect and secure. Manipulating the chains across the stacks can be unsafe, as the stacks of vehicles are unstable and are prone to slip or tip over.
Various alternative trailers are used to overcome these disadvantages. A common approach is the use of a three-sided trailer of the type disclosed, for example, in U.S. Pat. No. 5,599,058. A twelve-inch high retainer wall of solid sheet steel is also provided on the three walled sides around the bottom periphery to prevent any small pieces of debris from falling off the trailer bed on those sides. The open side of the trailer is located on the side of the transport vehicle that will be toward the berm of the road, so that any debris falling in that direction will fall to the side of the road.
In accordance with U.S. Pat. No. 5,876,164, there is provided a device for carrying car frames or the like, comprising a rectangular base member comprising at least one trailer bed, and means for mounting said base member on wheels. Transverse members are spacedly mounted on the base member and a first vertical protection wall is mounted at a front end of the base member. A second vertical protection wall is mounted on one longitudinal side of the base member, the other longitudinal side being free of vertical protection wall, and a third vertical protection wall is mounted at a rear end of the base member. Support means extend vertically from the transverse member and are aligned along a straight line spaced at an equal distance from the second protection wall. A non-slip member is disposed along the other longitudinal side of the base member, and means for securing a load of car frames are stacked on the transverse members between the support means and the non-slip members.
In accordance with a preferred embodiment, the base member comprises a front trailer bed and a rear trailer bed, the rear trailer bed being articulated to the front trailer bed, the first vertical protection wall being mounted at the front of the front trailer bed, the third vertical protection wall being mounted at the rear of the rear trailer bed, the second vertical protection wall being mounted on the longitudinal left sides of both front and rear trailer beds.
Despite advances of the type described above, the need remains for a trailer with a fourth side that opens and closes. In the United States, this need has increased in urgency due to a recently enacted law requiring that all four sides of car frame haulers be enclosed at least up to the level of the load.